This invention relates to an exercise device for strengthening abdominal muscles, and more specifically to a device which may be employed by a user without requiring assistance. The device is primarily employed in conjunction with a mattress and box-spring, and combined with its foldable and portable structure, enables it to be readily used in the home with various mattress sizes, as well as under a door, etc., and also may be carried on trips for use outside the home such as in hotels, etc.
Strengthening the abdominal muscles, and hence the support of the lower back, results in fewer back problems and also improves posture and overall fitness. Usually, some assistance is required to hold the user's feet stationary while an abdominal exercise such as a sit-up exercise is being performed. Typical patents in this field include U.S. Pat. Nos. 2,240,228; 3,134,592; 4,378,939; 4,508,335; 4,515,361; 4,550,907; 4,679,788; German patent 2,145,884; and Japan Patent 57-93354. The devices which are considered to produce the most effective results are those where the user can place both hands behind the head while securing the feet with some type of holding means and then performing a sit-up exercise. Preferably, an abdominal exercise device should accomplish the following: i. the user's knees and hips are bent or flexed; ii. the user's feet are anchored; iii. no irritation of the tail bone should occur; iv. the device should be inexpensive and portable; and, v. the abdominal exercise should be capable of being performed with a graded degree of difficulty.
U.S. Pat. Nos. 3,134,592; 4,515,361; and, 4,679,788 describe devices which can be used in conjunction with a mattress and box-spring, but the devices of these patents are not readily portable, or lightweight, and assembling and disassembling these devices would be time consuming. Also, these devices appear to require expensive components.
An exercise device is desired which can be used in the home and which can be readily assembled, or disassembled and stored. Also a portable device is desired which can be used away from the home in conjunction with a mattress and box-spring, or on a carpet, floor, etc., for example in a hotel.